Rishi Sunak will not take over as prime minister until Tuesday at the earliest, Downing Street has said, after he was selected as Tory leader on Monday afternoon.
The former chancellor won the race to succeed Liz Truss after rivals Boris Johnson and Penny Mordaunt both dropped out of the contest.
Speaking at Tory HQ after his victory, Sunak said he was “humbled and honoured” to become PM describing it as the “greatest privilege in my life”.
Under the standard procedure, King Charles will hold an audience with Sunak to appoint him PM, having first accepted Truss’ resignation.
Downing Street said discussions were “ongoing” over the precise timetable for Sunak to assume office. “There won’t be a transition today,” No.10 said.
Sunak will have to grapple with a painful cost of living crisis as well as the aftershocks of Truss’ mini-Budget which triggered chaos in the markets.
He also faces an uphill battle to unite his party and win the next election after the Tories saw their poll ratings tank.
Labour and other opposition parties have demanded Sunak hold a general election immediately.
He will be the second Tory prime minister since 2019 to enter No.10 without the public having voted for the party with them as leader.
But speaking to Tory MPs shortly after he was chosen as leader, Sunak ruled out holding a snap election.
The next general election does not have to be held until January 2025.
To make it onto the ballot, leadership candidates had to win the formal support of 100 MPs.
A Mordaunt campaign source said she fell just short, securing the backing of 90 MPs.
Johnson said 102 MPs were willing to nominate him, but he pulled out of the race late on Sunday evening.
At 42, Sunak will be the youngest UK prime minister of modern times. He will also be the first Hindu PM.
Angela Rayner, Labour’s deputy leader, demanded Sunak trigger a general election. “The Tories have crowned Rishi Sunak as prime minister without him saying a single word about how he would run the country and without anyone having the chance to vote,” she said.
Lib Dem leader Ed Davey said the Conservatives have “installed another out-of-touch” prime minister, adding: “The only way to end the chaos is a general election now.”